The enrichment schemes involve the plundering of timber and high-value minerals like gold, diamonds and coltan in eastern DRC and the creation of false payment and pension schemes for army sections that do not exist ('ghost soldiers').
Gold, diamonds, copper, coltan and cobalt began to flow out of Congo again thanks to these armies and the politicians who kept them there.
The region is fertile, and has gold, tin and coltan (used in mobile-phone chips); some of it goes in transit, legally and illegally, through Rwanda.
Most stopped coming because they could no longer find buyers for their nuggets of coltan, a metal used in electronic gadgets.
At the Humule coltan mine a few gumbooted miners scramble up a red-earth ravine where last year there were thousands.
The law tries to shame big buyers, such as Apple and Motorola, who use Congolese coltan, into dealing only with bona fide suppliers.
The oxide (which comes from an ore called coltan) is converted to a fluoride using hydrofluoric acid, and the fluoride is then reduced with liquid sodium.
Mr Kagame justifies his intervention on the grounds of Rwanda's own security but his army reportedly made £20m a month from mining coltan in 2000 and still exports quantities of diamonds and gold that were mined in Congo.
Elsewhere, according to a senior Rwandan officer who recently sought asylum in Belgium, the army hires Hutu militiamen to work its coltan mines.
The light planes go over [to Colombia] with guns and they come back with drugs".The cocaine business, along with illegal mining of gold and coltan, a mineral used in the manufacture of electronic devices, creates an almost insatiable demand for petrol and diesel, which are heavily subsidised by the Venezuelan government.
Apart from gold, they illicitly sell cassiterite (used in laptops), coltan (mobile phones) and wolframite (light bulbs).
